Field of the Invention
This invention relates to a conductor spool for securing excess lengths of a conductor. More particularly, the invention relates to a robust conductor spool with manufacture and installation efficiencies.
Description of Related Art
Fiber to the Antenna (FTTA) installations transmit data to a tower mounted transceiver, known as a Remote Radio Head (RRH) or Remote Radio Unit (RRU). A single composite cable may provide the power, signal and/or control conductors for an FTTA installation.
It is desirable to have high quality terminations for each conductor, to improve signal quality, power efficiency and system reliability. Terminating a conductor in a remote location, such as atop a radio tower, may require an increased skill/training level for the installation personnel and significantly increase the installation time.
Optical conductors may be fragile, requiring great care to properly terminate. Optical conductors may also be especially fragile and prone to damage if a minimum bend radius is not observed. By using a cable storage spool, an optical conductor (such as one or more optical fibers) may be compactly coiled at close to the minimum bend radius, with a significantly reduced chance of damage, as the spool surface sets the minimum bend radius and supports the cable against reduction of the winding diameter (for example if the conductor is subjected to tension from one end or the other).
Prior composite cable RRU/RRH terminations have employed an over-voltage protection and/or distribution box for terminating each of the electrical and optical conductors as individual jumpers. These additional enclosures require field termination of the several conductors atop the radio tower, increasing installation time and labor requirements. Further, each break in the conductors provides another opportunity for signal degradation and/or environmental fouling.
Factory terminated composite cable assemblies are known. However, it may be difficult to provide a single cable assembly for multiple installations as the exact lengths between attachment points may vary installation to installation. Manufacture of custom length composite cable assemblies may be cost prohibitive and prone to measurement error by the purchaser, requiring re-work and/or application of additional jumpers.
Conductor spools adapted for optical fibers are also known. However, these are typically overly complex and expensive to manufacture/install or light weight folded packet configurations suitable only for placement within surrounding enclosures. The folded packet configurations may be inexpensive, but fail to secure each end of the optical fiber from applying tension to the spool, requiring further retention hardware within the surrounding enclosure to prevent damage to the conductor due to over tightening of the coil.
Therefore, an object of the invention is to provide a conductor spool and optical/electrical composite cable assembly with conductor spool that overcomes deficiencies in the prior art.